Railway signaling



Feb. 8, 1938. H A. THOMPSON 2,107,678

RAILWAY S IGNALING Filed Sept. 18, 1956 2 Sheets-Sheet 2 Fig. 1B.

INVYENTOR HowardAflompmn.

H15 ATTORNEY Patented Feb. s, 1938 UNITED STATES PATENT ()FFiCE RAILWAY SIGNALING Howard A. Thompson,

Edgewood, Pa., assignor Application September 18, 1936, Serial No. 101,467

9 Claims.

My invention relates to railway signaling, and particularly to signaling involving wayside signals located along a trackway for governing the passage of trains.

A feature of my invention is the provision of novel and improved apparatus for establishing a distinctive control for each of. three sections in the rear of an. occupied section. Each distinctive control is effective to cause a corresponding aspect of the associated wayside signal whereby there is produced a three-block, four-indication, system of signaling.

I will describe one form of apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Figs. 1A and 1B are diagrammatic views which when placed end to end in the order named illustrate one form of apparatus embodying my invention.

Referring to the drawings, the reference characters l and 8 designate the rails of a stretch of railway track along which traffic normally moves in the direction indicated by the arrows. These rails are divided by insulated joints 9 into a plurality of track sections W-X, X--Y, and Y-Z.

As here shown, each track section is divided by insulated joints 9 into at least two sub-sections IT, 2T, 3T, 4T, etc; Each sub-section is track battery l0 connected across the rails at one end of the sub-section and a track relay, designated by the reference character 'I'R with a prefix the same as the numerical prefix in the reference character of the associated sub-section, connected across the rails at the other end of the sub-section.

To govern the passage of trains through the stretchof railway, a wayside signal designated 40 by a suitable distinguishing reference character,

is provided for each track section. Each of these signals includes an upper indication unit U and a lower indication unit L. Theseunits may take any one of several forms of signal mechanism such as semaphore, color light, searchlight, or position light. As here shown, each upper unit U is a semaphore arm capable of assuming a horizontal or "stop position, a or caution position, and a vertical or proceed position; and each lower unit L is a caution lamp Y capable of displaying a yellow light.

Operatively connected with each semaphore arm U is a contact H and a pair of. pole changi'ng contacts l8 and I9. Contact I! is in engagement with contact 20 at all times except when the provided with a track circuit which includes a semaphore arm is in the vertical position. Pole changing contacts l8 and I9 are in engagement with contacts 2| and 22, respectively, whenever the semaphore arm is in its 45 position or in its vertical position or at any point between these two positions, and are in engagement with contacts 23 and 24, respectively, whenever the semaphore arm is at any point below the 45 position.

Each semaphore arm U is provided with a lamp E which when lighted provides supplementary color light indications corresponding to the positions of the associated semaphore arm.

For controlling the associated signal, each section is provided with a polarized signal control relay, a neutral signal control relay, and an auxiliary relay designated by the reference characters HD, J, and JP, respectively, each with a prefix the same as the reference character of the associated signal.

For controlling the associated relays HD and J, each section is provided with a pair of conductors each of which extends to the signal next in advance and each of which includes a front contact of each of the associated track relays.

Each section is provided with an operating battery the terminals of which are designated by the reference characters B9 and C0 and each section is provided with a line battery designated by the reference character ll. Each line battery l is provided with a low voltage terminal, a high voltage terminal, and a common return terminal designated by the reference characters Bl, B2, and C, respectively.

Each relay I-ID is connected to the associated pair of conductors by signal contact l'l20 of. the associated signal. Each relay J is connected to the associated pair of conductors through a resistor l6.

Each relay JP is governed by the associated relay J. For example, relay I2JP is governed by a circuit which includes front contact 25 of relay I2J, so that relay IZJP will be energized or deenergized when relay IN is energized or deenergized.

As will be explained more in detail hereinafter, the pair of conductors for each section is at times supplied with energy of a relatively low value and at other times is supplied with energy of a relatively high value. The pickup value of the relays HD is such that these relays will become picked up upon receiving energy of either value whereas the pickup value of the relays J is such that these relays will become picked up only upon receiving energy of the higher value.

The signal pole changing contacts l8 and I9 and the relays HD and JP control the magnitude and direction of the energy supplied to the line conductors for the section next in the rear.

For controlling the signal lamps E and Y, each section is provided with an approach lighting relay designated by the reference character ER with a prefix the same as the reference character of the associated signal. The relays ER are connected in series with the line conductors for the section next in rear and therefore are energized at all times except when that line circuit is open. That is, the approach lighting relays ER become released to energize the associated lamp E and the control circuit for the associated lamp Y only when the section immediately to the rear of the signal with which such lamps are associated becomes occupied by a train.

The relays HD, J, and JP control the upper unit U and the lower unit L of the associated signal in the following manner: When the line circuit is opened so that all relays are deenergized (see signal 5 5) both semaphore arm U and lamp Y are deenergized so that signal I5 is displaying its semaphore arm in the horizontal position to indicate stop. When the relay HD is energized in the reverse direction (see signal l4), a caution circuit for the semaphore arm U of that signal is closed over a path which passes from terminal Bil over front contact 26 of relay MHD, semaphore arm U, and-front contact 21 of relay MHD to terminal C0. Semaphore arm U of signal M, therefore, is in the caution position to indicate approach next signal prepared to stop. When relay HD is energized in the normal direc tion (see signal l3), the'caution circuit for semaphore arm U remains closed over front contacts 2% and 21 of relay l3HD and a circuit is established for the lamp Y of the lower unit L of that signal. This circuit passes from terminal Bil over back contact 28 of relay I3ER, back contact 29 of relay I3J, front contact 30 of relay I3HD, normal polar contact 3l-32 of relay I3HD, and lamp Y to terminal C0. Signal l3, therefore, is displaying its upper semaphore arm U in the cantion position and a circuit for lamp Y is established so that when relay I3ER becomes released.

by a train approaching signal I 3 in section WX, this signal will display its semaphore arm in the caution position over a yellow light to indicate approach next signal at medium speed. When relay HD is energized in the normal direction and relays J and JP also are energized (see signal l2), the caution circuit for the upper semaphore arm U will remain closed over front contacts 26 and 2! of relay HD and a proceed circuit for the semaphore arm U will be closed over a path which passes from terminal B over front contact 26 of relay IZHD, front contact 33 of relay iZJP, semaphore arm U, and front contact 27 of relay IZHD to terminal C0. Signal l2, therefore, is displaying its semaphore arm in the vertical-position to indicate proceed at normal speed. When the semaphore arm U of signal i2 attained its proceed position, signal contact ill-29 became opened so that relay IZHD is released. Consequently, the caution and clear circuits for upper semaphore arm U are disconnected from the terminals B0 and C0 of the operating battery and are connected directly to the line conductors for the section WX over the back points of contacts 26 and 21 of relay IZHD.

As here shown, a train K is indicated diagrammatically in the section immediately to the right of location Z so that the signal l and associated relays are all deenergized. 1

When signal iii and associated apparatus is in this condition, relay l lI-ID is energized in the reverse direction by energy of a relatively low value over a circuit which passes from terminal Bl of battery ii at signal 15, through signal contact l9--24, back point of contact 3d of relay iEJP, front contact 35 of relay GTR, front contact 35 of relay 5TB, relay MHD, contact -28 of signal l4, front contact 3'! of relay 5TB, front contact 38 of relay ETR, back point of contact 39 of relay l5JP, contact 58-23 of signal i3, and relay IEER to terminal C.

When relay E li-ID is energized in the reverse direction, so that semaphore arm U of signal it is in the caution position, relay IEHD is energized in the normal direction by energy of relatively low value over a path which passes from terrelay MJP, contact l9-22 of signal 54, and relay HER to terminal C.

When only relay ifiHD is energized in the normal direction so that the semaphore arm U remains in its caution position, both relays IZHD and IZJ are energized in the normal direction by energy of relatively high value. The circuit for relay lZHD may be traced over a path which passes from terminal B2 of battery Hat signal l3, through normal polar contact t8 -l9 of relay" I3HD, front contact 5!] of relay i3HD, contact ill-2i of signal i3, back point of contact 5! of relay l3JP, front contact 52 of relay ZTR, front contact 53 of relay ETR, contact WZQ of signal When relay IZJ is energized so that relay lZJP' also is energized, the line conductors for the sece tion next in rear of location W are supplied with energy in the normal direction of relatively high value over front points of contacts 51 and 58 of relay I2JP so that the signal (not shown) associated with such conductors will be in condition to display the normal proceed indication.

The resistors l6, connected in series with the relays J, are of such value that the normal current flowing in such relays is just sufficient to hold the relays picked up. The relays J therefore, will be certain to become released when the energization of the associated line conductors is changed from the high value to the low value. A shunt path including a back contact 59 of the associated relay JP is provided around the corresponding resistor l5 in order that the relay J, when released, Will receive sufficient energy for pickup. The slow pickup characteristic of the relays JP is provided to insure that the shunt path will remain closed until such time as the associated relay J becomesv picked up. While the resistors it are here shown external to the associated relay J, these resistors may, if desired, be included as a portion. of the relay winding.

Furthermore, when the energization of the line conductors changed from the high value to the low value to provide a more restrictive indication, such line conductors are momentarily disconnected' from the source of energy so that the associated relay J will be even more certain to release. For example, when the direction of energization of the relay I3HD is changed from normal to reverse to change the energization of the line conductors for the section W-X from the high value to the low value, front contact 56 of relay l3l-ID will become momentarily opened to disconnect energy from the line conductors for the section W-X.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a section of railway track, a pair of conductors for said section, means for supplying said pair of conductors with energy of relatively low value in the reverse direction or with energy of said relatively low value in the normal direction or with energy of relatively high value in accordance with traflic conditions in advance of said section, a polarized relay responsive to energy of either value receiving current from said pair of conductors, a neutral relay responsive only to energy of said high value also receiving current from said pair of conductors,

a repeating relay for said neutral relay, a signal for said section comprising a first indication unit and a second indication unit, said first indication unit being a semaphore arm capable of assuming a stop and a caution as well as a proceed position and said second indication unit being a lamp, a caution circuit for said semaphore arm including a front neutral contact of said polarized relay, a proceed circuit for said semaphore arm including a front neutral contact of said polarized relay and a front contact of said repeating relay, and a circuit for said lamp including a front neutral and a normal polar contact both of said polarized relay as well as a back contact of said neutral relay.

2. In combinatiorna forward and a rear section of railway track, a polarized relay and a neutral relay for said forward section, means effective when the forward section is unoccupied to energize only said polarized relay in the reverse direction or only said polarized relay in the normal direction or both said relays according to traffic conditions in advance of said forward section, a pair of conductors for the rear section controlled by traffic conditions in that section, means effective to supply said conductors with energy of relatively low value in the reverse di rection when both said relays are deenergized, means effective to supply said conductors with energy of said relatively low value in the normal direction when said polarized relay only is energized in the reverse direction, means effective to supply said conductors with energy of a relatively high value when said polarized relay only is energized in the normal direction as well as when said neutral relay is energized, and trafiic governing means for the rear section receiving energy from said pair of conductors and selectively responsive to the value and direction of the current received therefrom.

3. In combination, a forward and a rear section of railway track, a polarized relay and a neutral relay for said forward section, means effective when the forward section is unoccupied to energize only said polarized relay in the reverse direction or only said polarized relay in the normal direction or both said relays according to trafiic conditions in advance of said forward section, a repeating relay which becomes energized or deenergized according as said neutral relay is energized or deenergized, a si nal for the forward section governed by said polarized relay and by said neutral relay, a pole changer having a contact which is closed when said signal is displaying a stop indication and another contact which is closed when said signal is displaying a proceed indication, a pair of conductors governed by traffic conditions in the rear section, means for supplying said conductors with energy of relatively low value in the reverse direction including said one contact and a back contact of said repeating relay, means for supplying said conductors with energy of said relatively low value in the normal direction including said other contact and a back contact of said repeating relay as well as a reverse polar contact of said polarized relay, means for supplying said conductors with energy of relatively high value including said other contact and a normal polar contact of said polarized relay as well as a back contact of said repeating relay, means for also supplying said conductors with energy of said relatively high value including a front contact of said repeating relay, and traflic governing means for the rear section receiving energy from said pair of conductors and selectively responsive to the direction and value of the current received therefrom.

4. A railway signal system comprising a stretch of track divided into sections, a track circuit including a track relay for each section, a pair of line conductors for each section each including a front contact of said track relay, means for each section for supplying the pair of conductors for the section next in rear with energy of relatively low value in one direction or with energy of said relatively low value in the other direction or with energy of relatively high value in accordance with traffic conditions in advance, a polarized relay for relay of a section is energized in said one direction to cause the associated signal to display a particular indication, means effective when only the polarized relay of a section is energized in said other direction to cause the associated signal to display a diiferent indication, and means effective when both relays of a section are energized to cause the associated signal to display still a different indication,

5. In combination, a stretch of railway track divided into sections each provided with a track circuit including a track relay, a pair of conductors for each section each including a front contact of the associated track relay, means effective when one section is occupied to supply the conductors for the section next in rear of such occupied section with energy of a particular magnitude and direction, means then effective to supply the conductors for the section second in rear of such occupied section with energy of the same magnitude but in the other direction, means then effective to supply the conductors for the section third in rear of such occupied section with energy of different magnitude, and traific governing means for each section receiving energy from the associated pair of conductors and selectively responsive to the direction and value of the current received therefrom.

6. In combination, a forward and a rear section of railway track,a polarized relay and a neutral relay for said forward section, means eiiective when the forward section is unoccupied to energize only said polarized relay in the reverse direction or only said polarized relay in the normal direction or both said relays'according to traffic conditions in advance of said forward section, a pair of conductors for the rear section controlled by traffic conditions in that section, a source of current having a high voltage terminal and a low voltage terminal, means efiective to connect said conductors in one direction with said low voltage terminal when both said reiays are deenergized, means effective to connect said. conductors in the other direction with said low voltage terminal when said polarized relay only is energized in the reverse direction, means efiective to connect said conductors with said high voltage terminai when said polarized relay only is energized in the normal direction or when said neutral relay is energized, and traffic governing means for the rear section receiving energy from said pair of conductors and selectively responsive to the value and direction of the current received therefrom.

7. In combination, a stretch of railway track divided into sections each provided with a track circuit including a track relay, a pair of conductors for each section each including a front contact of the associated track reiay, means effective when one section is occupied to supply the conductors for the section next in rear of such occupied section with energy of a relatively low value in one direction, means then efiective to supply the conductors for the section second in rear of such occupied section with energy of said relatively low value in the other direction, means then effective to supply the conductors for the section third in rear of such occupied section with energy of relatively high value in the said other direction, and trafiic governing means for each section receiving energy from the associated pair of conductors and selectiveiy responsive to the direction and value of the current received therefrom.

8, A railway signal system comprising a stretch of railway track divided into a plurality of successive track sections, a pair of conductors for each section governed by trafiic conditions in the associated section, control means for each section receiving energy from the associated pair of conductors and selectively responsive to the direction and value of the current received therefrom, means for each section governed in accordance with the condition of the associated control means for supplying the conductors for the section next in rear with energy of a particular direction and value or with energy of the same value but in the opposite direction or with energy of a difierent value, and traffic governing means for each section also controlled by the associated control means. i

9. A railway signal system comprising a stretch of railway track divided into a plurality of successive track sections, a pair of conductors for each section governed by trafiic conditions. in the associated section, control means for each section receiving energy from the associated pair of conductors and selectively responsive to the direction and value of the current received therefrom, means for each section governed in accordance with the condition of the associated control means for supplying the conductors for the section next in rear with energyof a particular direction and value or with energy of the same value but in the opposite direction or with energy of a different value, and a signal for each section capable of assuming three distinctive proceed conditions also governed by the associated control means.

HOWARD A. THOMPSON, 

